SOLAR TODAY - January/February 2010

new energy | for and about students and emerging solar professionals

tokai University Wins Global Solar Challenge

CL See videos from the race: solartoday.org/race

After 22 years of development, the cars have grown almost too sophis-
ticated. They’re required to abide by local speed limits, which keeps maxi-
mum highway speeds below 130 kph (80 mph), but with a loaded weight of
just 300 kilograms (660 pounds) and running
on very narrow low-friction tires, the cars are
fragile — several of the 31 starters suffered
delay due to flat tires and suspension damage,
and only eight cars ran the full distance. The
wing-like carbon fiber bodies, honed in wind-
tunnel testing, are vulnerable to crosswinds.
In fact the Belgian entry, Umicar, spun out of
control and was wrecked after encountering
a whirlwind. Another favorite, the Swisspirit
car, was damaged in shipping to Australia.
Last-minute repairs to the front suspension
and steering column didn’t stand up to tech-
nical inspection, and the car was withdrawn
before the start.

Tokai University’s car on Oct. 27 won the 11th running of the Global Solar Challenge race, a 3,000-kilometer (1,860-mile) endurance contest across Australia’s Outback, from Darwin to Adelaide.

Averaging 110.54 kilometers per hour (63 mph) over the four-day event, Team Tokai ran a flawless race and finished in 29 hours, 49 minutes, roughly an hour ahead of the sec-ond-place Nuva V, fielded by the Dutch Nuon team from Delft University. Nuon, which won the biannual race in 2001, 2003, 2005 and 2007, was plagued with early electrical problems and a flat tire. A dust storm on day two slowed all the cars.

shaRp co Rp.

Nuon was challenged for second place by the University of Michigan’s Infinium team.

The Tokai University solar car team consists of 19 students led by Hideki Kimura, professor of electrical and electronic engineering. The team and car won the 4,200-kilometer

( 2,600-mile) south african solar Challenge in 2008, as well as the 2009 Global solar Challenge.

The two cars swapped places several times, running very close on the final sprint into Adelaide.

The Tokai car is powered by 2,176 triple-junction compound indium gallium phosphide cells, developed by Sharp for the Japanese space program. The array covers 6 square meters and, at 30 percent conversion efficiency, generates 1.8 kilowatts. The cells charge a Panasonic 5.6-kilo- watt-hour lithium-ion battery pack and drive a Mitsuba brushless DC direct drive motor with claimed efficiency of 97 percent. —Seth MaSia